In manufacturing process of liquid crystal display (LCD) product, the manufacturing of the display panel includes many processes. Therefore, a conveyer is necessarily used for conveying display substrates.
In the prior art, a plurality of conveying rollers parallel to each other are usually provided. The display substrates may be transferred with the rotation of the conveying rollers. In this case, in order to avoid adverse influences of static electricity and moisture on the display substrates during the rotation of the conveying rollers, each of conveying rollers is usually provided with a plurality of rubber rings. The rubber rings may be rotated with the rotation of the conveying rollers, so as to allow the display substrates placed thereon to be conveyed. Since the rubber rings have good anti-static, water-proof and wear resistant properties, the rubber rings can protect the display substrates well during its transmission, and can prevent the display substrates from being damaged by the static electricity and the moisture.
The conveying rollers and the rubber rings are usually used for horizontally transferring the display substrate. During the horizontal transmission of the display substrates, actions such as position regulation of the display substrates, reading of the identification codes and adherence of the identification labels are necessarily completed on the conveying rollers and the rubber rings. To complete these actions, stop positions of the display substrates during the transmission are required to be highly accurate. Therefore, an offset angle of a transmission surface, which is formed by the rubber rings around the conveying rollers and which is used for supporting and conveying the display substrates, is required to be within 1-3° with respect to horizontal plane, and the fluctuation of flatness of the transmission surface is required to be within 0.2±0.1 mm. That is to say, the horizontal transmission of the display substrates requires the transmission surface, which is formed by the rubber rings and which is used for supporting and conveying the display substrates, to have a relatively high flatness. The flatness of the transmission surface depends on straightness of a row of rubber rings around different conveying rollers and having same sequence. That is to say, from ends at the same side of the conveying rollers, first rubber rings of respective conveying rollers are arranged into a line, second rubber rings of respective conveying rollers are arranged into a line . . . , and nth rubber rings of respective conveying rollers are arranged into a line. The better the straightness of a row of rubber rings having the same sequence is, the better the flatness of the transmission surface is. Meanwhile, the lines, into which the rubber rings are arranged, have to be in parallel with each other, such that the transmission surface can have a good flatness.
In this manner, a great number of rubber rings are provided, and the conveying rollers may apply a centrifugal force to the rubber rings during the rotation, such that the rubber rings may be displaced. Therefore, if a certain rubber ring is displaced too much from the line where it should be, the distribution of the rubber rings on the conveying rollers will be not uniform, such that the display substrates are caused to vibrate during the transmission and in turn to probably deviate from its travelling direction. This position offset is likely to lead to damage of the display substrates during the position regulation. Therefore, positions of the rubber rings are needed to be frequently regulated in the transmission process of the conveying rollers.
In a traditional method of regulating the positions of the rubber rings, the conveying rollers are stopped from rotating, and then the positions of the rubber rings are regulated manually. Or, during the rotation of the conveying rollers, the positions of the rubber rings are regulated by a steel ruler. Since in both of the regulation methods the positions of the rubber rings can be regulated one by one only, the regulation efficiency is very low. Further, it is difficult for manual regulation to accurately control the straightness of a row of rubber rings and to accurately control an interval between rubber rings, so that the flatness of the transmission surface formed by the rubber rings cannot be accurately controlled.